The MTA has this: https://bustime.mta.info/#B63 https://bustime.mta.info/#B63 The CTA has this: https://www.ctabustracker.com/bustime/wireless/html/eta.jsp?rou

The MTA has this: https://bustime.mta.info/#B63 https://bustime.mta.info/#B63 The CTA has this: https://www.ctabustracker.com/bustime/wireless/html/eta.jsp?route=4&direction=Northbound&id=1584&showAllBusses=on https://www.ctabustracker.com/bustime/wireless/html/eta.jsp?... Those are the only two cities I've lived in, but the ability to track buses seems widespread to me.